Hardware or software failure of a communication system has negative effects on the communication system performance. Uninterrupted communication services during a call or standby mode are sought-after attributes of a communication system. Hardware failure in particular would cause long delays in restoring the communication services.
Referring to FIG. 1, a simplified block diagram of a communication system 100 is shown. The communication system 100 may include a number of mobile stations such as mobile stations 101-02, more mobile stations are also possible, but here only two are shown, and a cell site 110 that may be divided into a number of sectors, such as sectors 111-13. Each mobile station communicates with the cell site 110, through at least one of the sectors, via a forward wireless link 121 and a reverse wireless link 122. Each sector would have associated hardware, such as base transceiver stations (BTS) 114-16. The BTSs 114-16 are connected to a base station controller (BSC) 117 that controls the operation of the BTSs 114-16, among other functions. The BSC 117 is connected to other networks or public switching network collectively shown at a block 199.
In each BTS, there are a number of hardware elements coupled with controlling software that provide the interface between the mobile stations and the remaining parts of the cell site. In particular, each BTS has a number of channel elements where each channel element provides hardware and software resources for controlling a communication link. Each communication link comprised of a forward link, a link from the BTS to the mobile station, and a reverse link, a link from the mobile station to the BTS. A channel element provides functions of the forward link encoding and modulation, data symbols addition (puncturing), and forward power gain adjustment. In addition, each channel element provides functions of the reverse link demodulation, frame quality determination, and reverse power control. A channel element may perform other functions. A BTS may have a number of channel elements. Few of the channel elements may not be in use some of the time. When a channel element fails in the communication system, the communication link that is serviced by the failed channel element is interrupted or terminated even though the link may have been serviced by other channel elements in the BTS.
Therefore, there is a need for method and apparatus in a communication system for allocating channel elements to a communication link such that failure of one channel element does not terminate or interrupt the communication link.